1. Field
The present embodiments relate to batteries for portable electronic devices. More specifically, the present embodiments relate to the use of graphene in the anode and/or cathode current collectors of batteries for portable electronic devices.
2. Related Art
Rechargeable batteries are presently used to provide power to a wide variety of portable electronic devices, including laptop computers, tablet computers, mobile phones, personal digital assistants (PDAs), digital music players and cordless power tools. The most commonly used type of rechargeable battery is a lithium battery, which can include a lithium-ion or a lithium-polymer battery.
Lithium-polymer batteries often include cells that are packaged in flexible pouches. Such pouches are typically lightweight and inexpensive to manufacture. Moreover, these pouches may be tailored to various cell dimensions, allowing lithium-polymer batteries to be used in space-constrained portable electronic devices such as mobile phones, laptop computers, and/or digital cameras. For example, a lithium-polymer battery cell may achieve a packaging efficiency of 90-95% by enclosing rolled electrodes and electrolyte in an aluminized laminated pouch. Multiple pouches may then be placed side-by-side within a portable electronic device and electrically coupled in series and/or in parallel to form a battery for the portable electronic device.
Recent advances in battery technology have also led to the development of solid-state batteries, in which electrodes and a thin solid electrolyte are layered on top of a non-conducting substrate. Because the solid electrolyte takes up less space and/or weighs less than the liquid electrolyte of a comparable lithium-ion and/or lithium-polymer battery, the solid-state battery may have a higher energy density than the lithium-ion and/or lithium-polymer battery. In addition, the solid-state battery may be safer and/or more reliable than conventional lithium-ion and/or lithium-polymer batteries. For example, the use of a non-flammable, solid electrolyte in the solid-state battery may allow the solid-state battery to sidestep liquid electrolyte hazards such as spilling, boiling, gassing, and/or fires.
However, solid-state batteries are typically associated with much higher manufacturing costs than other types of batteries. For example, the cathode current collector of a solid-state battery may be made of an expensive metal such as gold or platinum. In addition, the layers of the solid-state battery may be formed using a complex and/or costly technique such as vacuum deposition. Consequently, manufacturing techniques for solid-state batteries may be cost-prohibitive to consumer applications of the solid-state batteries.